1. Field of the Invention
The present invention relates to an image-capturing apparatus and image-capturing method applied, for example, to a digital camera, for detecting out-of-focusing state prior to capturing pictures in an appropriate manner.
2. Description of Related Art
Electronic camera devices such as digital cameras are equipped with display devices that can be used as monitors for confirming images during image-capturing operation. Images of subjects taken with this kind of digital camera are displayed as monitor images (so-called through-images) of a subject at the display devices after being subjected to photoelectric conversion by an image-capturing device such as a CCD (Charge Coupled Device) etc., signal conversion, and signal processing etc. A picture is then taken when a user presses the shutter at the desired timing while looking at the monitor image. The captured image of a subject after signal processing is then recorded and stored on a storage medium as recorded image data. The image information recorded to and saved on a recording medium may then be read out and reproduced at the display device such as a liquid crystal display or outputted to an external device.
Resolution of monitor images displayed at the display devices is usually lower than resolution of recorded images saved at a recording medium with these kinds of typical digital cameras. This means that images with lower definition than recorded images are displayed at the display devices. Giving an example of a certain type of digital camera on the market, resolution of recorded images is 640×480, while resolution of monitor images is 220×279. As a result, there is a problem that it may not be possible for a user to discern whether or not the captured image has become blurred due to camera-shake or being out-of-focus when a user presses a shutter at a time of watching the monitor image displayed on a liquid crystal display etc. of an image-capturing apparatus.
Digital cameras equipped with a function enabling part of an image to be displayed in an enlarged manner while playing back captured images therefore exist to overcome this problem. It is then possible for a user to enlarge part of the captured image to confirm focusing when using this kind of digital camera. In this event, it is necessary to follow through steps of image-capturing in recording mode, switching over to playback mode when the image-capturing has finished, and reproducing and enlarging the recorded image to confirm focusing, and then switching back to recording mode again if focusing is blurred in order to capture an image again. This therefore remains a complex and troublesome operations for a user. To address the above-described issue, there are proposed an electronic cameras capable of image-capturing while enlarging part of an image portion corresponding to a focused position of the captured monitor image in order to confirm focusing, and then displaying an enlarged captured image (for example, refer to Japanese Patent Application Publication JP 11-196301).